'Our procedure wasn't followed' at one security checkpoint at the gala, an agency spokesman says. The couple who attended uninvited had been auditioning earlier for a reality TV show.

Reporting from Washington — The Secret Service has launched a "comprehensive investigation" of its security measures after two aspiring reality-TV stars crashed President Obama's state dinner at the White House on Tuesday night.

Tareq and Michaele Salahi, who have been auditioning to appear on the Bravo reality show "Real Housewives of D.C.," strolled into the dinner honoring Indian Prime Minister Manmohan Singh and mingled with the power people of Washington -- even though they weren't on the invitation list.

More than a dozen photos were posted on Facebook showing the Salahis with various luminaries, including Vice President Joe Biden, White House Chief of Staff Rahm Emanuel and "CBS Evening News" anchor Katie Couric.

Secret Service spokesman Ed Donovan said initial results of the investigation showed that "our procedure wasn't followed" at one security checkpoint, allowing the uninvited guests to enter.

An administration official said the gate-crashing was apparently a breakdown in Secret Service screening and not the work of the White House social office.

The White House requested an investigation, but the Secret Service had already begun one after discovering the incident.

Donovan stressed that everyone at the party, including the gate-crashers, passed through rigorous safety checks.

"Everyone went through the other levels of security and the metal detectors," Donovan said Thursday.

Once inside, the couple easily blended into the crowd of more than 300. Tareq, in a tuxedo, and Michaele, in flowing red sari, looked like the perfect Washington couple.

The Salahis, Washington socialites who own a winery in northern Virginia, were introduced as they sauntered into the event area before a bank of cameras. "Mr. and Mrs. Salahi," an announcer said.

Whether they were actually seated during the event -- and were able to enjoy the dinner of curry prawns, roasted potato dumplings and pumpkin pie tarts -- is still unknown.

A Facebook page with the couple's name had photos of their adventure. "I was honored to be invited to attend the First State Dinner hosted by President Obama & the First Lady to honor India," said a caption with a photo of Michaele.

"A Sensational Night honoring India," said another.

Under a picture of Michaele with Biden was the caption: "OMG! SO EXCITING!!!!!! IRISH EYES ARE SMILING TOGETHER!"

Earlier in the day, a camera crew shooting for "Real Housewives" had spent hours filming the couple as they prepared for the state dinner. The cameras did not film the couple inside the White House.

Johanna Fuentes, a Bravo Media vice president for communications, said in an e-mail to the news service that the Salahis told the show's producer, contracted by Bravo, that they were invited, and the production company "had no reason to believe otherwise."

Paul Morrison, a Virginia attorney who has represented the couple in the past but has not spoken to them since the dinner, told the Associated Press on Thursday that he did not think the Salahis had done anything illegal.

"They just went to a party. They didn't do anything wrong," Morrison said. "I know them. I'm unaware of any reason they need representation right now."